The Government formally raised concerns with the US over covert surveillance by its National Security Agency in Ireland and in the EU, it has emerged.

A spokesman for Minister for Foreign Affairs Eamon Gilmore has confirmed he raised the matter earlier this summer at a senior level with the US Embassy in Dublin.

The move followed reports the NSA had bugged the Justus Lipsius building, the headquarters of the Council of the EU, in Brussels.

The fact the issue was raised with the US embassy was not disclosed last week by Taoiseach Enda Kenny when he was asked about the alleged bugging of German chancellor Angela Merkel’s phone. He said however he “always” operated on the basis that the calls he was making were all listened to.

Now it has emerged that Mr Gilmore, in reply to a parliamentary question in July confirmed: “The Government has already expressed our concerns to the US Embassy in Dublin at a senior official level”. In other comments, he said if it were true the EU building had been bugged “it would be the equivalent of the European Union bugging Capitol Hill”.

Meanwhile, a report in the Spanish daily El Mundo claimed the NSA ranks Ireland outside its closest intelligence collaborators. Citing a new cache of files provided by Edward Snowden, the newspaper says the US classifies co-operation with various countries on four levels.

In the first group, “comprehensive cooperation”, are the UK, Australia, Canada and New Zealand. The second, “focused co-operation”, comprises 19 countries. Ireland does not appear on the list. The third group, “limited co-operation”, consists of countries that are “not habitually hostile to the US”, according to the report. A fourth tier is made up of countries considered hostile.